Polychrome striped screens for color television receiver comprising filaments of homoneous glass



1968 P. I. PEYCHES 3,39

POLYOHROME STRIPED SCREENS FOR COLOR TELEVISION RECEIVER COMPRISINGFILAMENTS OF HOMOGENEOUS GLASS Original Filed Dec. 23, 1960 3Sheets-Sheet l IN VEN TOR.

PIERRE IVAN PEYCHES ATTORNEYS Aug. 27, 1968 P. l. PEYCHES 3,399,320

POLYCHROME STRIPED SCREENS FOR COLOR TELEVISION RECEIVER COMPRISINGFILAMENTS OF HOMOGENEOUS GLASS 3 Sheets-Sheet 2 Original Filed Dec. 25,1960 INVENTOR.

PIERRE IVAN PEYCHES BY ATTORNEYS Aug. 27, 1968 P. I. PEYCHES 3,399,320

POLYCHROME STRIPED SCREENS FOR COLOR TELEVISION RECEIVER COMPRISINGFILAMENTS OF HOMOGENEOUS GLASS Original Filed Dec. 23, 1960 3Sheets-Sheet 5 INV EN TOR.

PIERRE IVAN PEYCHES ATTORNEYS United States Patent 3,399,320 POLYCHROMESTRIPED SCREENS FOR COLOR TELEVISION RECEIVER COMPRISING FILA- MENTS OFHOMOGENEOUS GLASS Pierre Ivan Peyches, Paris, France, assignor toCompagnie de Saint-Gobain, Neuilly-sur-Seine, France Originalapplication Dec. 23, 1960, Ser. No. 78,077, now Patent No. 3,256,124,dated June 14, 1966. Divided and this application Dec. 7, 1965, Ser. No.512,155

Claims priority, application France, Apr. 30, 1959, 793,638; Apr. 22,1960, 824,986 6 Claims. (Cl. 313-92) This is a division of applicationSer. No. 78,077, filed Dec. 23, 1960, now US. Patent No. 3,256,124,dated June 14, 1966.

This invention relates to polychrome striped screens for use in colortelevision.

It is known that it is possible to reconstitute the color scale bycombination of at least three appropriate primary colors. This principleis the basis of the largest partof color television systems, whichutilize the principle of splitting an image into three monochromaticimages each of which is in one of three primary, coordinate colors; thethree images are transmitted electronically to the receiving screen.Generally these screens are of the polychrome type and are viewed withdirect vision. Some of the screens are made by the dot stippling ofpin-point elementary surfaces onto a transparent support and others aremade by the application to the support of parallel stripes. Dots andstripes are generally made of fluorescent substances which emit, underthe impact of an electronic beam, 21 light which is colored according tothat one color of the primary colors in the screen which is found in theparticular dot or stripe. The parallel stripes are preferable to thestippled surfaces, both for their luminous efficiency and for easiermanufacture.

It is also possible to use screens constituted by a film of pigmentswith white homogeneous luminescene, in front of which is placed aconveniently colored optical filter.

The manufacture of the polychrome screens with striped structure is verydifiicult due to the fact that the great number of stripes required fora good integration of the image and differentiation of the colors forthe observer, requires great fineness and exact parallelism of thestripes.

My invention has for an object the provision of striped polychromescreens for color television which have excellent characteristics offineness and regularity of linev According to the broad aspects of myinvention, the lines of the colored screen are made by mountingtransparent, colored glass filaments on a transparent support andcoating them with a uniform film containing pigments with whiteluminescence. Glass is particularly well adapted to the production ofuniform filaments having a diameter on the order of some tenths ofmillimeter, and the colors available in glass are every well adapted tothe polychromy of the television system.

The electrically conductive metal grid generally associated with priorscreens may be installed in the new screens with known electricalconnections and thus may be advantageously incorporated in the coloredfilter constituted by the glass filaments. Novel conducting filamentsmay be made of opaque glass rendered conductive by metallization,reduction, etc.

Due to their flexibility, the filaments constituting the screen areeasily adaptable to the shapes of the support panels of televisiontubes.

It is advantageous, in manufacturing the screen to produce a flexiblesheet of filaments joined side by side, which are thereafter applied onthe support, which may be the bottom of the tube, and are fixed there bya Patented Aug. 27, 1968 ice transparent enamel or by self-soldering. Inthis case it is advisable to select the glass compositions in order thatthe expansion coeflicient of the different filaments be practically thesame as that of the glass support. The glass filaments may be applied toa temporary support and joined by means of a combustible bindingmaterial, or they may be joined by depolymerizable resin such asmethylpolymethacrylate, or any other material able to be entirelyeliminated at higher temperature, before being applied to the permanentsupport which is part of the screen. After the application of the sheetof filaments to the bottom of the tube, and the elimination of binderand temporary support, the process of manufacture is the same as for atelevision screen in white and black, that is, sedimentation of asubstance with white luminescence and, if desired, metallization.

It is surprising that, in spite of the corrugation of the sheet on whichis placed the luminescent substance, the light transmission through eachglass filament seems homogeneous to the observer.

If the conductive grid be separated from the colored filter, it ispossible to utilize a separate metallic grid, the wires of which aremasked by non-transparent filaments of the same dimensions, which takethe place of the electrical conducting filaments in the screen describedabove.

It is an object of the invention to provide a novel and usefulpolychrome screen of the type which utilizes a homogeneous layer ofwhite luminescent pigments in association with an optical filter ofparallel colored band type. Another object of the invention is toprovide novel and useful methods for making the new screens. The objectsof the invention as to product are accomplished generally speaking by atelevision screen having a transparent glass support, a layer oftransparent enamel coating a face thereof, a multiplicity of contiguousfilaments of transparent colored glass arranged in parallel in repeatingsets containing at least three primary colors attached to the enamel,and a layer of material responsive to electronic rays covering thefilaments, and the objects as to process are accomplished by a method ofmaking a television screen that comprises mounting sets of red, greenand blue glass filaments on the surface of a glass support insubstantially contiguous and parallel relationship, and coating thefilaments with a coating responsive to bombardment by electronic rays.Other objects and accomplishments of the invention include novelelements which are useful in the invention and which will be describedand claimed hereinafter.

The screens of this invention may be used in color television processesbut this use is not a limitation as the screens are generally useful inexcitation by electronic rays, particularly cathode rays.

The above and further objects and novel features of the presentinvention will more fully appear from the following detailed descriptionwhen the same is read in connection with the accompanying drawings. Itis to be expressly understood, however, that the drawings are for thepurpose of illustration only and are not intended as a definition of thelimits of the invention, reference for this latter purpose being hadprimarily to the appended claims.

In the drawings wherein like reference characters refer to like partsthroughout the several views,

FIG. 1 is an apparatus adapted to the manufacture of the novel screens;

FIG. 2 is an enlarged section through one form of screen;

FIG. 3 is an enlarged section through a modified form of screen;

FIG. 4 is an enlarged section through a further modification;

FIG. 5 is a diagram of a television tube embodying a novel screen, aportion of the tube being broken away; and

FIG. 6 is an enlarged section taken out of the screen of FIG. 5.

EXAMPLE I Referring particularly to FIG. 1, there is shown a series ofglass supports which are carried by a conveyor (not shown) along apredetermined path to an oven 26. The glass supports 1 are transparentand of a size and thickness adapted for use in television tubes. Thesupports '1 are contiguous and pass in sequence below glass filamentforming apparatus 33, 34, 35, which are diagrammatically indicated beingof known construction. The device 33 forms a multiplicity of filamentsof green glass having a diameter suited to the manufacture of an opticalgrid, for instance about from 2/ 10 to 4/10 mm. Adjacent fibers areseparated by twice the diameter of a single filament. A guide receivesthe filaments 3 and lays them on the surface of the supports 1, whichare coated with a transparent enamel 2 of relatively low melting pointcompared to the glass 1. The melting point of the enamel 2 is such thatit will melt in the heat of the oven 26 and attach the filaments to thesupports 1. Comb 18 and roller 21 serve to maintain the exactparallelism and separation of the filaments and, by driving roller 21the progress of the filaments at the same speed as the supports isachieved. The apparatus 34 forms blue glass filaments 4 which are laidparallel and contiguous to green glass filaments 3 by guide 16, comb 19and roller 22. Apparatus 35 forms red glass filaments 5 which aredeposited continuously and parallel to filaments 4 and which will becontiguous to the next green glass filament in the series or not,depending upon whether the screen is to be of the type shown in FIG. 2or of the type shown in FIG. 3. The apparatus of FIG. 1 illustrates theformation of a screen of the type of FIG. 2 which is provided with theopaque interstitial enamel 28 of FIG. 4, consequently, in FIG. 1 thescreen produced will have contiguous and parallel filaments in series ofthree, each series containing a green, blue and red glass filament.

After passing by the comb 20 which maintains the alignment of all thefibers which have been deposited on the enamel, the fibers pass underthe roller 23, which sets them roperly in the enamel, and goes to adevice 24 which feeds loose dry enamel of opaque characteristic onto thesurface of the filaments. A brush 25 removes the enamel from the tops ofthe filaments leaving it in the interstices between the tops of thefilaments as shown at 28 in FIG. 4.

The supports 1 then pass into the oven which is maintained at atemperature between the melting points of the two types of enamel andthe melting point of the glass support 1. The enamel melts below andabove the fibers forming a uniform and transparent coat which attachesthe filaments to the supports 1 and provides the upper portions withinterstitial opaque areas which improve the optical qualities of thescreen.

When it is desired to make a screen of the type shown in FIG. 3, afourth fiber forming apparatus, similar to 33, is provided whichdeposits an opaque glass fiber 36 between each set.

After the screen is discharged from the oven it is cooled and a whiteluminescent layer 27 is applied over the tops of the sets of coloredglass filaments.

In this invention the layer of luminescent pigments for the screen canbe made as they are made for black and white tubes. These pigments areusually mixtures of zinc sulfide, and cadmium sulfide of high purityincluding activators which differ according to the manufacturer. Theseproducts are known and need not be described herein, particularly asthey are usually described in the sales literature of the companieswhich make them.

The standard glasses which are used in the formation of glass filamentsare useful in this invention and their compositions need not bedescribed as they can be derived from the published art dealing with themanufacture of glass fibers and filaments. It suffices to add theappropriate coloring material, usually metal salts, to the glasscomposition, for example for blue glass one adds a. small proportion ofcobalt salt to the glass batch. For green glass one may incorporatechromium and copper oxides. For red glass selenium, gold and copperprovide the color. In the manufacture of such screens it is notnecessary to rely upon the coordinate colors green, blue and red, itbeing possible to achieve a reconstitution of the visible spectrum bythe use of at least three coordinate primary colors of which green, blueand red are exemplary.

In order to avoid the difficulty that could be experienced because of adifference in coefiicient of expansion between the support and thefibers attached to it, the basic glass used for the preparation of thedilferently colored fibers can be the same as the variation in thecoefiicient of expansion which can result from the addition of thecoloring material would be sufficiently small. Moreover this glass canhave a coefficient of expansion sufiiciently close to that which is usedin the manufacture of television tubes to make the differenceunimportant.

Alternatively the sheet of filaments may be produced continuously anddirectly on a support constituted by a sheet of glass which is fiat orslightly transversely curved with respect to the direction of travel ofthe sheet. The glass sheet provided with the sheet of filaments is thencut to dimensions suitable for screens, and the panels may be thereaftershaped to the desired form.

EXAMPLE II Another method of manufacturing these novel screens is toapply to adhesive paper the sets of colored fibers in the order in whichthey are to appear on the glass support, covering the fibers with alayer of depolymerizable resins such as polymethyl methacrylate. Thepaper band is then removed, leaving the fibers attached to each otheronly by the resin. This provides a grid of fibers on a depolymerizableorganic support which can be eliminated by simple heating withoutleaving any traces. When this grid is applied to the support and thesupport is admitted to the oven the adhesive is volatilized before theenamel is coftened so that the attachment of the grid to the supportoccurs cleanly. In Example I there is direct application of the opticalgrid to the glass support. In Example II a transfer process is used inwhich the grid is applied to a support which can be eliminated without atrace. Among the novel grids which can be produced by this lnvention arethose which are shown in FIGS. 2, 3 and 4. In FIG. 2 item 1 is a supportwhich has attached to it by enamel 2 sets 3, 4, 5 of green, blue and redfilaments 1n repeating order, which are covered by a white luminescentcoat 27. This is a simple and very useful type of screen.

In FIG. 3 each set of three colored fibers is followed by a fiber ofopaque glass 36 above which, outside the white luminescent coat 27, is ametal wire 29 forming a part of the metal grid which is characteristicof color television systems in which there is an electrically conductivefilament, which need not be metal so long as it is conductive, aboveeach colored set. Under the impact of the cathode rays a beamperiodically engages the grid thus permitting a synchronization of thebeam in order that the three different colors blue, green and red beobtained in the desired order and at the desired location.

The transparent enamels of low melting point which are used to attachthe filaments to the support can be made with a base of lead oxide.

The metal wires 29 should be mounted behind the opaque filaments 36 sothat they will be invisible to the observer. The opaque glass filamentscan be made by incorporating manganese oxide, nickel oxide, iron oxideor cobalt oxide in the same glass as used for the other filaments.

In FIG. 4 there is shown a modification of some importance. In thisfigure the usual sets 3, 4, 5 of colored glass are separated byfilaments 30 which bear a conductive coat 31. One may obtain conductivetransparent coats on glass by supplying solutions of tin salt or ofantimony or indium salt. For example, one may spray on the desiredfi-bers an alcoholic solution of stannic chloride and antimony chlorideas the filaments issue, in FIG. 1, from a forming apparatus like 35, andwhich would follow immediately after the roller 23. Thus, in FIG. 4, thesets of three primary colors would be separated by means of opaquefibers with electrically conductive coats. These solutions would besprayed on the fibers at a temperature between 350 and 550 C. or atlower temperature. The solution should contain an ap propriate reducingagent such as formaldehyde or urea.

In a further modification of the invention the transparent enamel iseliminated from the surface of the sup port 1 and the temperature of theoven is carried to a point sufficient to soften the surface of thefibers or the surface of the support or both sufficiently to providemutual, homogeneous attachment, that is to say, they are self-sealed orself-soldered by heat.

In FIG. 5 is illustrated a television tube 32 in which a support 1 withits attached filaments forms the target. In FIG. 6 a section has beencut out of the screen and enlarged to show the relation of the parts,the numbers of which correspond to those which have been usedhereinabove.

Among the advantages of the invention are the production of screens andtargets of high utility and superior strength 'by new and convenientmethods of manufacture. A particular advantage of the invention is theelimination of the old laborious and inaccurate methods of applyingstrips to the face of the target. Another advantage is the provision ofstrips in the form of glass filaments whose diameters can be uniformlyand accurately controlled to correspond precisely to the width of theexciting rays. A further advantage is the adaptation of the new screensto particular television systems. Other advantages are in thepreparation of particular novel elements of structure and in thecombination of such elements with the other elements of the screens.

According to another embodiment of the invention, the sheet of filamentsmay be constituted by a warp comprising the colored filaments regularlydistributed in sets of three colors and by a loose weft entirelyelimina'ble, in the Weft being combustible or soluble (filaments ofsodium silicate).

As many apparently widely different embodiments of the present inventionmay be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments.

What is claimed is:

1. A television screen having a transparent glass support, a layer oftransparent enamel coating a face thereof, a multiplicity of filamentsof colored glass attached to the enamel in repeating sets of at leastthree primary colors, each filament consisting of homogeneous glass ofcircular cross-section which is tangentially in contact with thefilaments beside it, conjointly defining an engrailed surface, and acontinuous layer of white luminescent material covering the engrailedsurface.

2. A screen according to claim 1 further including a multiplicity ofopaque thread-like glass filaments, all said filaments being essentiallycircular in transverse section,

each said opaque filament being interposed between and separating eachtwo consecutive sets of said colored glass filaments, respectively.

3. A screen according to claim 2 and a multiplicity of electricallyconductive filaments, each said electrically conductive filament beingadjacent, fixed with, and parallel to a respective one of said opaquefilaments, on the side thereof remote from said transparent glasssupport.

4. A television screen having a transparent glass support, a layer oftransparent enamel coating a face thereof, a multiplicity of thread-likefilaments of transparent colored glass arranged in contiguous, parallel,side-by-side relation and in repeating sets each containing at leastthree primary colors attached to the enamel, and a layer of fluorescentmaterial covering the filaments, said threadlike filaments beingcircular in transverse section, each filament being tangentially incontact with the filaments on either side thereof, to conjointly definean engrailed surface, and opaque material distributed uniformly in andalong the indentations of said engrailed surface, remote from saidtransparent glass support, said material interconnecting said filaments.

S. A television screen having a transparent support having a smoothcontinuous surface, a layer of enamel attached to and covering saidsmooth surface of said support, a multiplicity of vitreous, parallel,transparent filaments of round transverse section arranged side by sideand in repeating sets, each said set including filaments of differentcolors and attached to said layer of enamel in contiguous relation, alayer of luminescent material overlying and attached to the engrailedsurface remote from said support, conjointly defined by said filaments,said filaments being in tangential contact, and stripes of opaque enamelwithin the channels of the engrailed surface conjointly formed by thefilaments on the side remote from said support.

'6. A television screen having a transparent glass support, a layer oftransparent enamel coating a face thereof, a multiplicity of thread-likefilaments of transparent colored glass arranged in contiguous, parallel,side-by-side relation and in repeating sets each containing at leastthree primary colors attached to the enamel, a multiplicity of opaquethread-like glass filaments, all said filaments being essentiallycircular in transverse section, each said opaque filament beinginterposed between and separating each two consecutive sets of 'saidcolored glass filaments, respectively, and an electrically conductivecoating enrobing each said filament of opaque glass.

References Cited UNITED STATES PATENTS 2,446,249 8/1948 Schroeder 313-65X 2,512,123 6/1950 Weimer 178-5.4 2,657,331 10/1953 Parker 313-92 X2,700,697 1/1955 Houghton 178-5.4 2,706,262 4/1955 Barnes 313-922,734,013 2/1956 Myers 313-925 X 2,750,525 6/1956 Palmer 313-922,757,112 7/1956 Hoyt 313-925 2,796,374 6/1957 Donahue 154-95 2,858,23310/1958 Yanagisawa et al. 313-92 X 2,867,749 1/1959 Charlton 313-92 X2,955,348 10/1960 Healy 313-92 X 3,023,137 2/1962 Colborne et al. 156-673,027,219 3/ 1962 Bradley 346- 3,136,912 6/1964 Evans et al. 313-1083,160,774 12/1964 Guy 313-92 3,213,190 10/1965 Mutschler 178-5.4

ROBERT SEGAL, Primary Examiner.

1. A TELEVISION SCREEN HAVING A TRANSPARENT GLASS SUPPORT, A LAYER OFTRANSPARENT ENAMEL COATING A FACE THEREOF, A MULTIPLICITY OF FILAMENTSOF COLORED GLASS ATTACHED TO THE ENAMEL IN REPEATING SETS OF AT LEASTTHREE PRIMARY COLORS, EACH FILAMENT CONSISTING OF HOMOGENEOUS GLASS OFCIRCULAR CROSS-SECTION WHICH IS TANGENTIALLY IN CONTACT WITH THEFILAMENTS BESIDE IT, CONJOINTLY DEFINING AN ENGRAILED SURFACE, AND ACONTINUOUS LAYER OF WHITE LUMINESCENT MATERIAL COVERING THE ENGRAILEDSURFACE.